Celebrating Chemistry - CHEMISTSCELEBRATEEARTHWEEK AMERICANCHEMICALSOCIETY - American Chemical Society
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Celebrating Chemistry CHEMISTS CELEBRATE EARTH WEEK AMERICAN CHEMICAL SOCIETY
Dive into Marine Chemistry!
By Alex Madonik
W hen you think of the ocean, what images come to
mind? Huge waves? Giant whales? Mysterious
shipwrecks? Oceans cover almost three-quarters
of the earth’s surface and can be miles deep, so they are indeed
full of wonders. Life on our planet began in the oceans, and
The salt in the ocean started out as minerals on the land that
dissolved and were carried to the sea by rain. Some turned into
solid rocks such as limestone (calcium carbonate), the same
material that seashells and corals are made out of. Table salt
is very soluble in water, so it accumulates in the ocean. Two
today the oceans are full of tiny organisms that, together, weigh famous bodies of water that are very salty are the Great Salt
more than everything that lives on land! The oceans also absorb Lake in Utah and the Dead Sea in the Middle East. Because these
carbon dioxide and produce oxygen in a cycle that is essential lakes are not connected to rivers or creeks that can carry water
for all life on earth. away, the water can only evaporate, leaving behind the salt it
Marine chemists study the oceans to understand these contained. Salt mines are ancient salt lakes that completely
cycles. They also find food and useful chemicals in the oceans, dried up and were buried under deep layers of sediment.
in everything from fish to seaweed. The deep oceans contain many creatures that survive
Unfortunately, these chemists also find waste products from without light. Without light, no plants can grow there, but some
our daily lives. Plastic bags and nets injure birds, fish, and creatures make energy from elements in the water such as
marine mammals. Tiny plastic particles fill the water thousands sulfur or iron in a process called chemosynthesis. Many deep-
of miles from land. These particles harm marine life, not only sea creatures make their own light through a process called
because they are dangerous if swallowed, but also because bioluminescence — like underwater fireflies! The deep ocean
they attract oily chemicals that are poisonous to birds and fish. can be very cold, or it can be boiling hot near undersea thermal
Chemicals that escape from factories and even our homes flow vents. Amazing creatures live there also, and chemists are still
into the ocean. Pollution comes from small leaks and big spills. studying their secrets to figure out how they survive.
The first time you visit the ocean, you might be surprised In this issue of Celebrating Chemistry, you’ll learn more
by how salty the water is. Unlike rivers and lakes, the oceans about topics like minerals in the ocean, oil spills, and
contain about 3.5% salt by weight (mostly sodium chloride — bioluminescence. So join us in taking a dive into marine
the same as table salt). You can collect sea salt by evaporating chemistry!
the water in the sun, as people have done for thousands
of years. As the water evaporates, the salt becomes more Alex Madonik, Ph.D. is an Instructor of Chemistry at Peralta
concentrated. Certain kinds of colorful algae and shrimp can Community College in Oakland, California.
grow in this salty solution, which is called brine.
Curiously, scientists are not certain about where all the water
on earth came from. When the earth formed 4.6 billion years
ago, it was too hot to keep water around. It’s possible that water
arrived much later, carried by comets or asteroids that collided
with the earth.
2
Seashells: Antacids of the Ocean
By Jacqueline Erickson
Introduction
H ave you ever wondered what coral or seashells are made of?
Coral and some seashells contain a mineral called calcium
carbonate, which makes up chewable antacid tablets like
Tums®. Because of the nature of calcium carbonate, coral and some
seashells can be affected by increased carbon dioxide in the air.
Safety Suggestions
✓ Safety goggles required
✓ Protective clothing suggested
✓ C over your workspace with newspaper or paper towels to
Follow these instructions to see how calcium carbonate is affected absorb spills
by carbon dioxide. ✓ Do not eat or drink any of the materials used in this activity
✓ Thoroughly wash hands after this activity
✓ D
isposal: Dispose any liquid waste down the drain, and
Materials dispose solid waste in the trash
• 2 4-ounce (113 g) clear disposable cups or containers
• 1 marking pen
• 1 pack of chewable calcium carbonate antacid tablets
(colored tablets preferred)
How does it work? Where’s the chemistry?
• 2 ounces (56 g) seltzer water Regular tap water is neutral or slightly basic (with a pH value
• 2 ounces (56 g) tap water of 7). However, when carbon dioxide is added to water to
create the bubbles in seltzer water, carbonic acid is formed,
• Newspaper or paper towels to absorb spills
which lowers the pH value of the water making it acidic
(with a pH value of 4).
Procedures The antacid tablets contain calcium carbonate, which is
• U sing the marking pen, label one cup “Tap Water” and the other a base (with a pH value of 11). As bases react with acid, the
cup “Seltzer Water.” acidic seltzer water dissolves the calcium carbonate tablet
• Place one chewable calcium carbonate tablet in each cup. faster than the tap water.
• Add 2 ounces of tap water to the cup labeled “Tap Water” and add 2 Similarly, if there is more carbon dioxide in the air, the
ounces of seltzer water to the cup labeled “Seltzer Water.” Do not stir. ocean will absorb the carbon dioxide, and carbonic acid will
form, thus making the ocean water more acidic. Chemists call
• Observe what happens. Is there any difference in how fast the
this process acidification.
tablets dissolve?
This simple experiment demonstrates that dissolving more
• Record your observations after 1, 2, and 3 minutes, using the
carbon dioxide in water could destroy seashells or coral, as
Data Table. they are made of calcium carbonate. Based on this principle,
farmers sometimes use ground up seashells to make their
What do you see? soil less acidic. They work as antacids on land, too!
Data Table
pH Scale
Observation Time Tap Water Seltzer Water
Neutral
Acid pH Base
1 minute 1 2 3 4 5 6 7 8 9 10 11 12 13
2 minutes
Jacqueline Erickson is a Senior Development Scientist and Research
3 minutes & Development Project Leader at GlaxoSmithKline Consumer
Healthcare in Warren, New Jersey.
ALWAYS: • B
e sure to clean up and dispose of materials
• Work with an adult. properly when you are finished with an activity.
• Read and follow all directions for the activity. • Wash your hands well after every activity.
• Read all warning labels on all materials being used. NEVER eat or drink while conducting an experiment,
• Use all materials carefully, following the directions given. and be careful to keep all of the materials away from
• Follow safety warnings or precautions, such as wearing your mouth, nose, and eyes!
gloves or tying back long hair. NEVER experiment on your own!
3
Colors Under the Sea
By Richard Rogers
W hen you dive into the ocean and look around, several
things appear to change. The water acts like a magnifier,
and colors change as the sea water filters out red light, making
Chemical structure
of coelenterazine
things appear blue. As you look around more, you see a lot of
sea life in many colors. Why are some of these creatures almost
invisible, while others are brightly colored?
There are many answers. Some creatures’ colors help them
avoid being seen. Others have vivid colors that help them appear How does this reaction work? There are two parts that are
dangerous and scare off predators. Some, like the clown fish necessary. One is called a luciferin, which is the light-emitting
(remember Nemo?), are colored to blend into places that are safe compound, while the other is called a luciferase, which is the
for them but poisonous for other fish. Still others are brightly chemical enzyme that triggers the light-producing reaction. There
colored to show off for potential mates. are many different chemicals that can act as a luciferin, including
As you go deeper in the ocean, the light begins to fade until coelenterazine, the most widely-known one in marine life.
everything around you is totally black. How do deep sea creatures This evolutionary “trick” helps the organisms see in the darkness.
know what is going on, and not run into each other? Some It can also help a deep sea creature send out messages like “Here I
scientists believe that 75-90% of deep sea creatures use a natural am!” to others of its kind, or it can be shut off so that the creature
chemical reaction that produces visible light. This process is called can hide. There are even some fish that use the light to lure others
bioluminescence. It is thought that this process evolved hundreds close so that they can eat them. Sometimes at night on the coast,
of millions of years ago and includes several different chemical the sea seems to light up when the smaller plankton or krill light up
reactions. This is similar to fireflies or lightning bugs that can the whole area. Keep an eye out to see the colors in the sea.
be seen in several parts of the U.S. This chemical reaction is not
unique to any species or type, but is spread across a diverse set of Richard Rogers is a Senior Research Chemist at Grain Processing
creatures including squid, plankton, and even some bacteria. Corporation in Muscatine, Iowa.
Word Search
Try to find the words listed below – they can be
horizontal, vertical or diagonal, and read
Word Search
forward or backward!
Try to find the words listed below — they can be horizontal vertical or diagonal, and read forw
ACIDIFICATION P C A R B O N A T E S W G S G
ALGAE Y H K E S D E E W A E S K I A
ALGINATE B I O L U M I N E S C E N C E
BIOLUMINESCENCE D T A T W M B R I N E Q I H S
BRINE I I L A O H O E H W S D J T T
CARBON DIOXIDE
E W G R A S U L M N I C N S N
CARBONATES
N Q I J E W Y U E F P A K S E
CORAL
I I N C V M E N I C T F A H V
MARINE
R R A F O A Y C T C U L G C L
MOLECULES
PHOTOSYNTHESIS
A P T N G R A L A H I L G P A
POLYMER
M Y E L D T A F O N E R E P M
SALINITY L Q A N I L R L I P X S L S R
SEAWEEDS X E K O A U A T L A B J I A E
SURFACTANTS O A N H S K Y P U L Q Y W S H
THERMAL VENTS E D I X O I D N O B R A C B T
Word Bank
For answers to the word search, please visit the
ACIDIFICATION
ALGAE
Celebrating
ALGINATE Chemistry Archive at www.acs.org/ccew.
BIOLUMINESCENCE
BRINE
4 CARBON DIOXIDE
CARBONATES
CORAL
MARINE
MOLECULES
PHOTOSYNTHESIS
POLYMER
SALINITY
SEAWEEDS
Salt Water Rainbows
By Sanda Sun
Introduction
T he amount of salt in a body of water affects its density.
In fact, some bodies of water, like the Great Salt Lake
and the Dead Sea, contain huge amounts of salt,
allowing people to easily float on the water. How can you tell
when one body of water will be denser than another? Follow
✓ S
✓ D
Safety Suggestions
afety goggles required
o not eat or drink any of the
materials used in this activity
these instructions to compare the densities of different salt
✓ T horoughly wash hands after
water solutions.
this activity
✓ W ear gloves to prevent stain on hands
Materials ✓ C over your work area with newspaper or similar material to
• 7 teaspoons (about 35 mL) salt absorb any spills
• 1 quart (about 1 liter) water ✓ D isposal: All solutions can be safely poured down the drain.
• 1 permanent marker Solid materials should be disposed of in the trash.
• 1 teaspoon
• 4 stir sticks or plastic spoons
• 1 set of 4 assorted food colorings
• 4 clear plastic drinking straws
• 1 small test tube or narrow jar
• 4 8-ounce (about 235 mL) foam or plastic cups
Procedures
1.
L abel your 4 cups “0,” “1,” “2,” and “3” with the marking pen. 11. P
lace your index finger firmly on the other end of the straw
2.
Fill each cup half-full of water. and remove the straw from the solution.
3.
Add 5 drops of yellow food coloring in cup “0.” 12. P
ut the straw over the test tube or narrow jar and remove your
4.
Add 5 drops of blue food coloring in cup “1.” finger from the straw to release the water into the test tube.
5.
Add 5 drops of green food coloring in cup “2.” If a narrow jar is used, hold it at a slant and pour the solutions
6.
Add 5 drops of red food coloring in cup “3.” down the side of jar to avoid mixing.
D 7.
issolve 1 teaspoon of salt in the blue water in the cup 13. Repeat steps 10-12 with the green, blue, and yellow solutions.
marked “1.” 14. Draw a picture of your results.
8. D
issolve 2 teaspoons of salt in the green water in the cup 15. W
hat would happen if you repeated the experiment but put the
marked “2.” colored salt water in the test tube in a different order?
9. D
issolve 3 teaspoons of salt in the red water in the cup Now try it!
marked “3.”
10. D
ip the straw 1/2-inch into the red salt water solution in the Sanda Sun, Ph.D. is a Professor of Chemistry at Irvine Valley College in
cup marked “3.” Irvine, California.
How does it work? Where’s the chemistry?
The density of the solution increases as the amount of salt increases. The denser solutions stay on the bottom, and the less
dense solutions float on top of solutions of greater density. The result is a four-colored rainbow! The rainbow effect would not
form if the order were reversed. The denser solution would fall downward and contaminate the less dense solution.
5
Dive into Marine Chemistry!
1
7
5
6
8
6
By Lily L. Raines
11. The letters S-C-U-B-A in scuba diving stand
for “self-contained underwater breathing
apparatus.” Scuba divers use tanks
containing regular air, with 80% nitrogen
and 20% oxygen, or they can use air with
a higher oxygen content (32-36%) to avoid
decompression sickness (also known as “the
bends”), which can happen if someone dives
too deep and comes up too quickly.
22. Seawater contains many minerals, including
gold! There are almost 20 million tons of gold
dissolved in all the earth’s oceans. However, it
is so dilute it cannot be extracted. Looks like
the Moles can’t get rich off of seawater!
33. Seashells are the main source of calcium
carbonate found in sedimentary rocks, like
limestone. Seashells can be used to repair
damaged oyster reefs, to treat wastewater, to
make cement and calcium supplements, and
to adjust soil acidity in farms.
44. Kelp is a type of seaweed that grows mainly
in cool waters off the west coast of North
America. Because kelp use photosynthesis
to convert sunlight to energy, they do not
2 normally exist deeper than 49-131 feet
beneath the surface.
55. Some fish contain more heavy metals
than others (such as mercury) due to
bioaccumulation. This happens when fish eat
a compound, or absorb it through their skin,
faster than they can break down and excrete
it. Biomagnification is when this process
continues as you move up the food chain.
4 This is why many of the fish that you should
eat less of, such as tuna and swordfish,
happen to be high up the food chain. Visit the
Community Event page at www.acs.org/ccew
to learn more.
66. Not all mercury is the same! Sometimes we
add ethyl mercury to flu vaccines to help keep
them free from bacteria and fungi. The type
of mercury that can make people sick from
seafood is called methyl mercury. This small
chemical difference makes a big difference in
our health and safety!
77.
3 Many organisms that live deep in the
ocean can’t get any visible light, so they
use chemosynthesis instead. To do this,
they store energy from chemical reactions
with inorganic (non-carbon containing)
compounds as organic (carbon containing)
compounds like sugars. Most animals that
use chemosynthesis get their iron and sulfur
“food” from hydrothermal vents.
88. Many deep sea creatures use
bioluminescence to help them see in the
dark, to find each other, and to lure their
food to them. You can see examples of
bioluminescence in plankton on the surface at
one of the world’s five bioluminescent bays.
Lily L. Raines, Ph.D. is the Manager of Science
Outreach at the American Chemical Society in
Washington, D.C.
7
Seaweeds: Nature’s Marine Chemists
By M
elanie Daniels,
Sheila Kanodia,
and Cary Supalo
W hat looks like a plant but has no roots, stems,
or flowers, and lives in water? If you guessed
seaweed, you are right! This amazing family of
algae has more than 10,000 varieties across the world. Some
types are microscopic, while underwater forests of giant kelp
can be 40 feet tall!
Seaweeds provide food and homes for many fish, abalone,
crabs, and sea otters. Seaweeds are strong, and can help protect
ocean habitats from wave damage. Seaweeds are also an
ecosystem’s ‘chemists.’ They use photosynthesis to turn sunlight
into chemical and metabolic energy, and to capture carbon dioxide
from the water and release oxygen. Seaweeds and other algae also
make most of the world’s oxygen, which we need to breathe.
Seaweeds are found in many colors and shapes. Their major and sweet spices to make a drink called dulce. Seaweeds are
colors are red, green, and brown. Red seaweeds like cold water, found in many snack foods, including some crackers and
and green seaweeds prefer warmer tropical waters. Both types even ice cream.
live close to the shore, where the water is shallow enough As they grow, seaweed ‘chemists’ create many new
for sunlight to reach them. Seaweeds need light to grow molecules, including natural polymers. Polymers are
and make their own food. giant molecules that are made by putting many small
The shore has rocky places for the seaweeds to hold molecules together. For example, starch is made from
onto. The largest seaweeds are brown, and are tall sugar molecules. Seaweeds make natural polymers
enough to reach the light when anchored in deeper water called alginates. One of the most common alginates
far from shore. Sargassum is a type of seaweed that is known as sodium alginate. This substance absorbs
doesn’t have to anchor itself. It uses gas-filled sacs to help water, growing in size as it does, and provides support
it float. Other types of seaweed can survive in tidal pools, for seaweeds. Alginates are typically sold as powders.
where the temperature, saltiness, and water levels can When mixed with water, they can be as thin as pancake
change quickly. The names of different seaweeds give us batter, or as thick as cream cheese. In the ocean, it forms a
clues about their shapes. What do you think feather boa jelly-like substance.
kelp looks like? Or sea lettuce? Have you ever been to the dentist to get a mold made
Seaweeds have many uses. They are used for of your teeth to see if you needed braces? If so, the dentist
medicine, fertilizer, food, and possibly (in the future) fuel. probably used an alginate. Alginates are also in foods like
Seaweeds give us fiber and many important vitamins, trace yogurt and ice cream, because they give these foods that
elements, and minerals we need for good health. These special thick and creamy texture that we know and love.
minerals include calcium, magnesium, potassium, and The next time you think about the ocean, remember
iodine. Seaweeds have been used to keep wounds from getting how seaweeds help you every day. When you take a breath,
infected. They may also help in treating cancer. brush your teeth, or eat a healthy snack, seaweeds, the
Some people call seaweed a sea vegetable. People who ocean’s chemist, are part of your life.
live near the ocean discovered how to use it as food. In
China and Japan, people dry sheets of red seaweeds to Melanie Daniels is an Educator in Fairfield, California;
use in soups or for wrapping sushi. Seaweeds are used Sheila Kanodia, Ph.D. is Forensic Scientist at U.S.
in Wales (a country that is part of the United Kingdom) to Department of Homeland Security in Oakland, California;
make laverbread. In some places, seaweed is used to make and Cary Supalo, Ph.D. is President and Founder of
noodles. In Belize, seaweeds are mixed with milk Independence Science in Princeton, New Jersey.
8
Oil Spill!
By Alex Madonik
Safety Suggestions
Introduction
✓ S afety goggles required
How do you clean up an oil spill at sea? In this
✓ P rotective clothing suggested
activity, you’ll try out different methods of cleaning
✓ C over your work area with newspaper or a similar material to absorb any spills
oil spills. It’s time to act like environmental chemists
✓ D o not eat or drink any of the materials used in this activity
and engineers, and use your knowledge to try and
✓ T horoughly wash hands after this activity
clean up the “mini-oil spill” you create! You can do
✓ D isposal: Separate as much oil as possible from the water. Oil wastes should
this activity on your own or in a small group.
be disposed of in the trash. Water containing small amounts of oil should be
mixed with detergent and poured down the drain.
Materials
• 1 quart (about 1 liter) tap water • 2 feathers (purchase from a craft store to • 1-2 drops of “grease-fighting” dishwashing
• 3 drops blue food coloring ensure the feathers are clean) detergent
• 1 aluminum pie pan • 1 tablespoon (15 mL) vegetable oil • Tweezers or tongs for handling the types of
• 1 plastic spoon for skimming oil • Various items that might absorb oil, such as products that might absorb the oil
from the pie pan cotton balls, paper towels, oil-absorbing facial • 1 small plastic cup for collecting skimmed
• Paper towels tissues, and discarded pieces of fabric oil and water
How does it work?
Procedures Where’s the chemistry?
1. F ill your aluminum pie pan half-full of tap water. Add 3 drops of blue food coloring
and stir. This is your ocean! Oil and water don’t mix because water is
2. Add 1 tablespoon of vegetable oil to the water and stir. Describe what happens to the a polar substance and oil is a non-polar
oil. This is your mini oil spill! substance. Oil will float to the surface of
3. Draw what a clean feather looks like in Table 1. Place one feather in the oily water. After the water since it is less dense than water.
30 seconds, remove the feather from your oil spill, and draw what you see in Table 1. Skimmers are machines used to remove
Based on what you observe, what impact do you think an oil spill might have on birds? the oil that is sitting on the surface of
4. Use the spoon to skim the oil from the surface of the water. Put any recovered oil into the water. In a real oil spill, chemists
the small cup. Try to take only the oil off the surface, and not remove water. Rate your and engineers not only have to clean the
success at removing the oil. water, but they also have to clean any
5. Test the items you think will absorb the remaining oil and see which one removes the animals that may have gotten oil on their
most oil. Record your results in Table 2. fur or feathers. Surfactants, or soaps, are
6. Add 1-2 drops of “grease-fighting” dishwashing detergent to the oily water in your used to help break apart the oil into little
aluminum pie pan. Stir it with the spoon. Describe what happens to the remaining oil. droplets within the water. Then, microbes
7. Take your second feather and dip it into the pie pan. After 30 seconds, remove the can break down the oil to clean the water
feather and compare it to the one you dipped into the oil spill at the start of the in a way that scientists and engineers
experiment. Describe or draw what you see in Table 1. doing the cleanup cannot.
What did you see? Alex Madonik, Ph.D. is an Instructor of Chemistry at
Peralta Community College in Oakland, California.
TABLE 1
Clean feather Feather in oil spill Feather in oil spill with dishwashing detergent
TABLE 2
Oil-Absorbing Item How Well Did It Work? (1 = worst, 5 = best)
0 1 2 3 4 5
0 1 2 3 4 5
0 1 2 3 4 5
0 1 2 3 4 5
The Adventures of
Meg A. Mole,
Future Chemist Personal Profile
• Favorite food – Italian
• Favorite color – Blue, like the ocean
• F avorite pastime/hobby – Reading books by
Robert Ludlum and watching sports
• A
ccomplishment you are proud of – His high school,
undergraduate, and graduate students who have
published papers from their labs studies with him
• A
bout your family – Wife Judith, two sons, one daughter,
and two granddaughters
• F un fact – For years, he ran every day, and participated in
10 marathons and a half-marathon in Rome, Italy.
Now, he enjoys swimming for 30 minutes every evening in
Dr. Frank J. Millero his pool at home.
Ocean Chemistry Researcher
In honor of this year’s Chemists Celebrate Earth
Week theme, “Dive into Marine Chemistry,” I traveled all
I used the set to study the properties of natural systems (local
waters and salts) … and had only one explosion! In junior high
the way to Miami, Florida to meet with Dr. Frank J. Millero, and high school, I enjoyed studying chemistry, math, and Edgar
Professor Emeritus in the Department of Ocean Sciences at Allen Poe’s poetry.”
the University of Miami, Rosenstiel School of Marine and His interest in the sciences continued on after high school.
Atmospheric Science. After graduation, he went to a small college (Thiel College) to work
Dr. Millero explained to me that he “studies the physical on his bachelor’s degree. “I had a math teacher who used calculus
properties of the world’s oceans and other natural waters.” Most to study the Sputnik space flights,” he recalled. “After injuring
of his team’s studies, he told me, involve learning about the my knee playing football, I transferred to Ohio State, where I took
impact of carbon dioxide in the world’s oceans. I was not quite every chemistry course that was available, which included all the
sure why they study this, so I asked him to tell me more. laboratory courses in physical chemistry and calculus. Before
“We are interested in how CO2, a product from burning going to graduate school, I worked a summer at the National
fossil fuels, ends up in the oceans,” he said. “This addition of Bureau of Science under the direction of Roger Bates, a solution
CO2 causes the surface waters to have a lower pH, a problem chemist. I made thermodynamic measurements on solutions and
known as ocean acidification. My research group has been taking decided I wanted to get my Ph.D. in physical chemistry, so I got
measurements aboard research cruises for many years.” The team my Ph.D. at Carnegie Mellon.”
adds the data they and other researchers collect into a database After graduating from Carnegie Mellon, Dr. Millero took a job
that allows them to track the effects over time. Their results and with ExxonMobil working on automobile air pollution. “Later, I saw
those of other workers are published in scientific journals. an ad for a position at the University of Miami,” he explained, “and
I was very interested in how they do their work, and what I have been studying the chemistry of ocean waters ever since.”
tools they use. He told me, “Most of the equipment that we use, He has enjoyed teaching marine chemistry to undergraduate
we have developed ourselves.” I know safety is a very important students and marine physical chemistry to graduate students, and
aspect of all scientific work, so I wanted to know more about the many of his students have gone on to careers in chemistry and
personal protective equipment they used. “We normally do not published papers on the field.
need to wear safety glasses on cruises; however, in the lab when “I retired from teaching at the end of 2015,” he told me, “but
working with acids we would use them,” he said. I still have ongoing research projects and am active in studies of
Dr. Millero told me he was interested in chemistry at an early ocean chemistry. I have also enjoyed helping my granddaughters
age. “I sold seeds to buy my first chemistry set in grade school. with their many projects in chemistry.”
10By Al Hazari
Minerals from Sea Water
By Al Hazari
H ave you ever had chocolate candy flavored with sea salt?
Or, enjoyed delicious sea salt caramel ice cream?
Table or regular salt is mostly sodium chloride. But
recently, sea salt has become popular in fancy foods. What does
sea salt have that regular table salt doesn’t? It contains minerals
come from the presence of 84 trace minerals including potassium,
magnesium, and calcium. Iron oxide is the main element that gives
the salt its signature color. The salt comes from deep under the
Himalayan mountain range, where ancient seas evaporated more
than 200 million years ago. Another example is Brittany Grey Sea
from the sea. As a result, sea salt seems to taste ‘less salty’ and Salt, from France. It has a grey color that comes from minerals that
more ‘minerally’ than regular salt. are absorbed by the crystals from clay in the salt ponds. Finally,
For this reason, some people, including famous chefs, find that Persian Blue Salt is one of the rarest salts on earth and is harvested
sea salt tastes better than salt from underground salt mines. Some from the remnants of an ancient salt lake in Iran. The salt crystals
say it is also more nutritious and healthy. However, there is little or no seem to interact with light and produce its unique color.
health benefit to using sea salt over other forms of sodium chloride. Sometimes,
Seawater covers 70% of earth’s surface, and contains important additives are manually
mineral resources. There are a small number of major minerals mixed with white sea
in seawater, along with many minor (or “trace”) minerals. The salt to introduce a
major chemical elements are sodium, chlorine, magnesium, specific color. Hawaiian
sulfur, calcium, and potassium. A few examples of the minor Red Salt comes from
elements, those present in amounts less than about 400 PPM the addition of small
(parts per million), are bromine, nitrogen, phosphorus, iodine, and amounts of alae, or
manganese. There are also almost 20 million tons of gold dissolved red volcanic clay, to
in all the earth’s oceans! However, extracting any of these minerals the unrefined sea salt.
is very difficult. Today, direct extraction of the mineral resources is Cyprus Black Salt’s
limited to salt and magnesium. jet-black color is due to
Seawater contains about 3.5% dissolved salts by weight. This the addition of activated charcoal. The charcoal helps give the salt a
means that if you evaporate 100 grams of seawater, you are left unique flavor as well as more nutritional benefits.
with 3.5 grams of salt. Sea salt (sometimes called “bay salt” or With all these interesting colors of delicious table salt, why
“sun salt”) is produced through evaporation of the seawater, usually worry about extracting magnesium from the ocean? In the human
with little processing. Besides sodium chloride (table salt), it body, every cell requires magnesium to function. Magnesium
contains many trace minerals and elements. The minerals may add compounds are used as laxatives and antacids (for example, Milk
flavor and may also introduce a color to sea salt. of Magnesia). Many people add Epsom salts (magnesium sulfate)
Sea salt comes in a variety of colors depending on where in to their bath or spa. Seawater contains a bit more than 1,000 PPM
the world it is extracted. The colors range from white to pink, magnesium. That’s about one gram in a liter of seawater. In the
black, green, orange, blue, and others (see photo). For example, U.S., two-thirds of magnesium metal, and many magnesium salts,
the translucent pink hues of Himalayan Pink Salt (from Pakistan) are extracted from seawater.
In summary, seawater contains many minerals and metals. The
extraction of minerals and metals from seawater is happening now. But
the need for more of these substances to produce everyday consumer
products is likely to increase in the future. How much more money
would we be willing to pay for these seawater resources?
Al Hazari, Ph.D. is a retired Director of Labs and Lecturer in
Chemistry at the University of Tennessee in Knoxville, Tennessee.
11Words to Know What is the American
Acidification: the process of carbon dioxide dissolving in water, which creates carbonic acid. Chemical Society?
Algae: many different types of plants, from tall to tiny, that grow in the ocean. The American Chemical Society (ACS)
Alginate: a water-soluble polymer created by algae. is the largest scientific organization in
Bioluminescence: the ability of certain animals (such as fireflies and deep-sea creatures) to the world. ACS members are mostly
create light using chemistry. chemists, chemical engineers, and other
Brine: highly concentrated salt water, ranging from a mildly salty mix, where fresh water enters the professionals who work in chemistry
ocean, to over 30% salt in the Dead Sea. or chemistry-related jobs. The ACS has
nearly 157,000 members. ACS members
Carbon dioxide: also called CO2, this invisible gas appears in small amounts in regular air, and is live in the United States and different
created when animals exhale, people burn fuels, volcanoes erupt, or plants decay. countries around the world. Members
Carbonates: minerals formed when CO2 dissolves in water, including the most common type, of the ACS share ideas with each other
chalk (calcium carbonate). Corals and seashells are made of carbonate minerals. and learn about important discoveries in
Coral: tiny sea creatures that grow together to form giant colonies called coral reefs. chemistry during scientific meetings held
around the United States several times a
Marine: a word describing anything about the oceans.
year, through the use of the ACS website,
Molecules: tiny, individual chemical parts of the world around us. Everything is made of chemicals. and through the many peer-reviewed
Photosynthesis: how plants create food by taking in carbon dioxide and turning it into useful scientific journals the ACS publishes.
molecules such as sugar, using sunlight for their energy. The members of the ACS carry out many
Polymer: a giant molecule built from long chains of smaller molecules. programs that help the public learn
Salinity: the saltiness of water. about chemistry. One of these programs
is Chemists Celebrate Earth Week, held
Seaweeds: the many kinds of red, green, and brown plants that grow in the ocean. annually during the week of Earth Day
Surfactants: chemicals, like soap, that dissolve in both water and oil and help them mix. on April 22. ACS members celebrate
Thermal vents: places in the deepest parts of the ocean where incredibly hot water shoots out of by holding events in schools, shopping
cracks and holes in the ocean floor made by volcanoes. malls, science museums, libraries, and
even train stations! Activities at these
events include carrying out chemistry
Celebrating Chemistry investigations and participating in
is a publication of the ACS Office of Science Outreach in conjunction with the Committee on Community contests and games. If you’d like more
Activities (CCA). The Office of Science Outreach is part of the ACS Education Division. The Chemists information about these programs,
Celebrate Earth Week (CCEW) edition of Celebrating Chemistry is published annually and is available free of please contact us at outreach@acs.org.
charge through your local CCEW Coordinator. Please visit www.acs.org/ccew to learn more about CCEW.
PRODUCTION TEAM The activities described in this publication are intended for elementary school
David C. Horwitz, Editor Eric Stewart, Copyeditor children under the direct supervision of adults. The American Chemical Society
Rhonda Saunders, Designer Beatriz Hernandez, Translator cannot be responsible for any accidents or injuries that may result from conducting
Jim Starr, Illustrator the activities without proper supervision, from not specifically following directions,
or from ignoring the cautions contained in the text.
TECHNICAL AND SAFETY REVIEW TEAM
REFERENCES
Lynn Hogue, Consultant, Committee on Community Activities
Bettyann Howson, Safety Reviewer https://www.acs.org/content/dam/acsorg/education/outreach/cced/CCED-2014-
David A. Katz, Safety Reviewer Celebrating-Chemistry-English.pdf
Michael McGinnis, Chair, Committee on Community Activities http://ocean.si.edu/ocean-acidification
Ingrid Montes, Translation Reviewer https://www.popsci.com/oyster-shells-alternate-uses
Michael Tinnesand, Scientific Adviser Bioluminescence in the Sea, Steven H.D. Haddock, Mark A. Moline, and James F. Case
https://en.wikipedia.org/wiki/Seawater
https://pixabay.com/en/salt-sea-salt-salt-crystals-cook-602215/
CCEW 2018 THEME TEAM
https://www.monticelloshop.org/020650.html
Alex Madonik (Team Chair) George Fisher George Ruger https://simple.wikipedia.org/wiki/Seaweed
Richard Rogers (CCEW Chair) Al Hazari Sanda Sun http://sciencing.com/seaweed-kids-8642059.html
Jacqueline Erickson Sheila Kanodia Cary Supalo http://www.foodmatters.com/seaweed-superfoods
http://oceanservice.noaa.gov/facts/seaweed.html
DIVISION OF EDUCATION https://www.pmel.noaa.gov/eoi/nemo/explorer/concepts/chemosynthesis.html
https://www.tdisdi.com/nitrox-when-to-dive-it/
LaTrease Garrison, Executive Vice President
https://www.popsci.com/oyster-shells-alternate-uses
Lily L. Raines, Manager, Science Outreach
http://extoxnet.orst.edu/tibs/bioaccum.htm
David C. Horwitz, Program Manager, Science Outreach
https://www.nrdc.org/stories/smart-seafood-buying-guide?gclid=EAIaIQobChMIzOHs95
TG1wIVxSOBCh1r9wgKEAAYAiAAEgJJWvD_BwE
ACKNOWLEDGEMENTS
https://www.cdc.gov/vaccinesafety/concerns/thimerosal/faqs.html
The articles and activities used in this publication were written by members of the http://biolum.eemb.ucsb.edu/myth.html
ACS Committee on Community Activities. Meg A. Mole’s interview was written by https://oceanservice.noaa.gov/facts/kelp.html
Kara M. Allen.
© 2018 American Chemical Society, Education Division, Office of Science Outreach
1155 Sixteenth Street NW, Washington, DC 20036, 800-227-5558, outreach@acs.orgYou can also read
